Thursday, December 27, 2012

Torii Hunter Substantially Improves Tigers Outfield Defense

In previous posts, I took the Revised Zone Rating (RZR) and Out-of-Zone Plays (OOZ) metrics listed at FanGraphs
and converted them to runs based on an algorithm developed by Colin
Wyers a few years ago. Links to these posts are provided below:

Now, I'm going to to do the run conversion for right fielders. Table 1
below contains the following information for 18 MLB right fiielders with 800
or more innings in 2012:

Inn = Innings

RZR = Revised Zone Rating

OOZ = Out-of-Zone Plays

PIZAA = Plays in Zone Above Average

OOZAA = Out-of-Zone Plays Above Average

PMAA = Total Plays Above Average

RSAA = Runs Saved Above Average

Alex Rios of the White Sox led the
majors with +26 Runs
Saved Above Average. He was followed by Braves right fielder Jason Heyward at +26. The worst right fielder by this metric was Jeff Francoeur of the Royals
(-25).

When the Tigers acquired Torii Hunter earlier this off-season, they saw him as an upgrade both offensively and defensively. The Tigers' most frequent right fielder last season was Brennan Boesch who cost the Tigers an estimated -11 runs defensively according to RSAA. In contrast, Hunter was an estimated +11 runs better that the average right fielder. If his defense is the same in 2013, that would be a +22 run or two win improvement over Boesch.

What is interesting is how the two outfielders got to their final run saved/cost figures. According to these zone rating statistics, Boesch was actually better than Hunter on in-zone plays last year (+5 versus -1). However, Hunter was a stunning 32 plays better outside the zone (+13 versus -19). So, we can expect Hunter to cover a lot more ground in the outfield in 2013 than Boesch did in 2012.